Monday, July 14, 2014

Mega Blast Of Cool Air and Possible Flooding.



Everything is still on track in my opinion.  I wanted to use this post to key in on the potential for heavy rain later this week and exactly where this will set up.  That will be very crucial in determining the severity of any flooding.

Before I get into that, there will be a slight risk for severe weather for much of central, eastern, and northern Arkansas later Monday as the cold front moves through the state.  Wind and hail will be the main threats.  Tuesday and Wednesday look absolutely incredible with well below average temperatures and low humidity.  Record lows will be challenged and I have a list of all the potential records in the post below.

Like I said, the location of the heaviest rainfall is in question.  There will be a significant disturbance arriving Thursday into Friday and flooding is a concern.   The past few model runs have consistently indicated southern Arkansas could receive in excess of 3 inches.  The NAM, which only goes out to 84 hours, brings the heaviest rainfall into northern and central Arkansas, but this model can be a little "sketchy" that far out at times.  Due to this, I'm not buying it right now.  The GFS shows more widespread heavier amounts while the Euro has been "rock solid" indicating southern Arkansas.  You have to pay attention when a model stays consistent and it's a well respected model.  I have great concern for a few areas of the state which have already received copious amounts of rain over the past couple of weeks.  The first is east central Arkansas around Brinkley and the other is over Polk county and other areas of southwestern Arkansas.

Let's go to the maps....

The borders may be a little difficult to see here, but I have outlined the areas of heaviest rainfall over the past 2 weeks according to Doppler radar.  The primary areas of concern would be east central Arkansas, southwest Arkansas, the River Valley near Russellville, then far NE Arkansas.

From weatherbell.com, this is the overnight run of the GFS indicating widespread amounts of 2 inches or more with some heavier rains over eastern Arkansas which could reach up to 3''.
This is the European model from weatherbell.com showing total rainfall through Saturday and it has been ROCK SOLID indicating the heaviest rainfall across the southern half of Arkansas.  The amounts indicated here would reach 2-4 inches with some isolated higher amounts.  The northern sections of the state would get an inch or less.  My forecast, at this time, would lean towards this scenario.
Remember, the NAM only goes out to 84 hours and it's "Sketchy" towards that 84 hours as well.  By Thursday AM it shows the area of big rains, but it's located over NE Oklahoma into western and northern Arkansas.  This shows more than 3'' up there.  It will be interesting to see how future model runs handle this next disturbance and we'll see whether this model sees something the others don't or will it trend towards the Euro?
Manual progs from the WPC broad brushes central and southern Arkansas with at least 3 inches of rainfall over the next 5 days.  Some of this would fall late Monday, but the majority of it will fall later in the week.
Now onto temperatures...  2 meter readings, just off the surface, indicates lows Wednesday morning in the 40s and 50s.  I'm not going this cool at this time, but this would shatter records!
This too is the GFS from weatherbell.com and it shows high temperatures at 2 meters Thursday afternoon.  You can see clearly see where clouds and rain will hold temperatures down across northern and central Arkansas.  This shows readings staying in the 60s!  That would shatter records as well, but I'm not going this cool at this time.
Onto Friday afternoon, highs are around 70 degrees.  Once again, this would shatter records, but I think it will be a little warmer than this.  That will still be well below average.

No comments: